Add 3x/scripts/integral_demo.py

docs/3x/scripts/integral_demo.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+
+# implement the example graphs/integral from pyx
+from pylab import *
+from matplotlib.patches import Polygon
+
+def func(x):
+    return (x-3)*(x-5)*(x-7)+85
+
+ax = subplot(111)
+
+a, b = 2, 9 # integral area
+x = arange(0, 10, 0.01)
+y = func(x)
+plot(x, y, linewidth=1)
+
+# make the shaded region
+ix = arange(a, b, 0.01)
+iy = func(ix)
+verts = [(a,0)] + list(zip(ix,iy)) + [(b,0)]
+poly = Polygon(verts, facecolor='0.8', edgecolor='k')
+ax.add_patch(poly)
+
+text(0.5 * (a + b), 30,
+     r"$\int_a^b f(x)\mathrm{d}x$", horizontalalignment='center',
+     fontsize=20)
+
+axis([0,10, 0, 180])
+figtext(0.9, 0.05, 'x')
+figtext(0.1, 0.9, 'y')
+ax.set_xticks((a,b))
+ax.set_xticklabels(('a','b'))
+ax.set_yticks([])
+show()